Appears to be mostly obsolete in modern Japanese, superseded by the term 大きさ (ōkisa, “size”, literally “bigness”), from adjective 大きい (ōkii, “big”). The modern Japanese term with the reading of ōsa is 多さ (ōsa, literally “much-ness, many-ness”), from adjective 多い (ōi, “many, much”), deriving from the same Old Japanese root opo as 大きい (ōkii, “big”).